/* jsmin.c
   2008-08-03

Copyright (c) 2002 Douglas Crockford  (www.crockford.com)

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

The Software shall be used for Good, not Evil.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

#include <iostream>
#include <sstream>
#include <boost/thread/tss.hpp>

using namespace std;

#define DEFAULT_JSMIN_ENABLED true

static boost::thread_specific_ptr<bool> jsmin_enabled;

bool is_jsmin_enabled_for_thread()
{
	bool *enabled = jsmin_enabled.get();
	if(enabled)
		return *enabled;
	else
		return DEFAULT_JSMIN_ENABLED;
}

void set_jsmin_enabled_for_thread(bool b)
{
	bool *enabled = jsmin_enabled.get();
	if(enabled)
		*enabled = b;
	else
		jsmin_enabled.reset(new bool(b));
}

void unset_jsmin_enabled_for_thread()
{
	bool *enabled = jsmin_enabled.get();
	if(enabled)
		jsmin_enabled.release();
}


class JSMinifier
{
	private:
		stringbuf sb;
		const char *theCode;
		int idx;
		int theCodeLen;
		int theA;
		int theB;
		int theLookahead;
		
		int isAlphanum(int c)
		{
		    return ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') ||
		        (c >= 'A' && c <= 'Z') || c == '_' || c == '$' || c == '\\' ||
		        c > 126);
		}
		
		int get()
		{
		    int c = theLookahead;
		    theLookahead = EOF;
		    if (c == EOF)
			{
		        //c = getc(stdin);
				c = idx < theCodeLen ? theCode[idx++] : EOF;
		    }
		    if (c >= ' ' || c == '\n' || c == EOF) {
		        return c;
		    }
		    if (c == '\r') {
		        return '\n';
		    }
		    return ' ';
		}


		/* peek -- get the next character without getting it.
		*/

		int peek()
		{
		    theLookahead = get();
		    return theLookahead;
		}


		/* next -- get the next character, excluding comments. peek() is used to see
		        if a '/' is followed by a '/' or '*'.
		*/

		int next()
		{
		    int c = get();
		    if  (c == '/') {
		        switch (peek()) {
		        case '/':
		            for (;;) {
		                c = get();
		                if (c <= '\n') {
		                    return c;
		                }
		            }
		        case '*':
		            get();
		            for (;;) {
		                switch (get()) {
		                case '*':
		                    if (peek() == '/') {
		                        get();
		                        return ' ';
		                    }
		                    break;
		                case EOF:
		                    fprintf(stderr, "Error: JSMIN Unterminated comment.\n");
		                    exit(1);
		                }
		            }
		        default:
		            return c;
		        }
		    }
		    return c;
		}


		/* action -- do something! What you do is determined by the argument:
		        1   Output A. Copy B to A. Get the next B.
		        2   Copy B to A. Get the next B. (Delete A).
		        3   Get the next B. (Delete B).
		   action treats a string as a single character. Wow!
		   action recognizes a regular expression if it is preceded by ( or , or =.
		*/

		void action(int d)
		{
		    switch (d) {
		    case 1:
		        sb.sputc(theA);
		    case 2:
		        theA = theB;
		        if (theA == '\'' || theA == '"') {
		            for (;;) {
		                sb.sputc(theA);
		                theA = get();
		                if (theA == theB) {
		                    break;
		                }
		                if (theA == '\\') {
		                    sb.sputc(theA);
		                    theA = get();
		                }
		                if (theA == EOF) {
		                    fprintf(stderr, "Error: JSMIN unterminated string literal.");
		                    exit(1);
		                }
		            }
		        }
		    case 3:
		        theB = next();
		        if (theB == '/' && (theA == '(' || theA == ',' || theA == '=' ||
		                            theA == ':' || theA == '[' || theA == '!' ||
		                            theA == '&' || theA == '|' || theA == '?' ||
		                            theA == '{' || theA == '}' || theA == ';' ||
		                            theA == '\n')) {
		            sb.sputc(theA);
		            sb.sputc(theB);
		            for (;;) {
		                theA = get();
		                if (theA == '/') {
		                    break;
		                }
		                if (theA =='\\') {
		                    sb.sputc(theA);
		                    theA = get();
		                }
		                if (theA == EOF) {
		                    fprintf(stderr, "Error: JSMIN unterminated Regular Expression literal.\n");
		                    exit(1);
		                }
		                sb.sputc(theA);
		            }
		            theB = next();
		        }
		    }
		}

	public:
		JSMinifier()
		{
			theLookahead = EOF;
		}
		
		string minify(string codeStr)
		{
			if(!is_jsmin_enabled_for_thread())
				return codeStr;

			const char *code = codeStr.c_str();

			// stringbuf buf;
			// sb = &buf;

			theCode = code;
			theCodeLen = strlen(theCode);
			idx = 0;

		    theA = '\n';
		    action(3);
		    while (theA != EOF) {
		        switch (theA) {
		        case ' ':
		            if (isAlphanum(theB)) {
		                action(1);
		            } else {
		                action(2);
		            }
		            break;
		        case '\n':
		            switch (theB) {
		            case '{':
		            case '[':
		            case '(':
		            case '+':
		            case '-':
		                action(1);
		                break;
		            case ' ':
		                action(3);
		                break;
		            default:
		                if (isAlphanum(theB)) {
		                    action(1);
		                } else {
		                    action(2);
		                }
		            }
		            break;
		        default:
		            switch (theB) {
		            case ' ':
		                if (isAlphanum(theA)) {
		                    action(1);
		                    break;
		                }
		                action(3);
		                break;
		            case '\n':
		                switch (theA) {
		                case '}':
		                case ']':
		                case ')':
		                case '+':
		                case '-':
		                case '"':
		                case '\'':
		                    action(1);
		                    break;
		                default:
		                    if (isAlphanum(theA)) {
		                        action(1);
		                    } else {
		                        action(3);
		                    }
		                }
		                break;
		            default:
		                action(1);
		                break;
		            }
		        }
		    }

			string result = sb.str();

			return result;
		}
};



string jsmin(string codeStr)
{
	JSMinifier min;
	return min.minify(codeStr);
}
